FDA is cautioning doctors and patients about the serious complications that can occur when using medications not approved for use with implanted pumps that deliver medication into the spinal fluid to treat or manage pain. Complications may include dosing errors, pump failure, opioid withdrawal, and infection, not to mention pain, muscle spasms, cognitive changes, weakness, and cardiac or respiratory distress.
“The treatment of pain has become increasingly complex. While medical devices, such as implanted pumps that deliver medication directly into the spinal fluid, have the potential to play an important role in treating pain, their use must be judicious and their instructions for use must be carefully followed. This is especially true when it comes to implantable pumps that deliver analgesic medicine directly into the nervous system,” said FDA Commissioner Scott Gottlieb, MD. “We urge healthcare providers, patients and caregivers to be aware of the information the FDA is providing today so they can make informed treatment decisions."
Gottlieb said the agency will continue to monitor the safety of these and other medical devices involved in the treatment of pain, and take action where needed to protect patients.
Implanted pumps require a health care provider to periodically refill the pump with medication. Intrathecal delivery of medication with an implanted pump for pain management is generally reserved for patients who are not adequately managed by other pain treatments.
Currently, FDA-approved implanted pump labeling identifies pain medicines that have been evaluated by FDA for compatibility with the pump, including Infumorph and Prialt. However, not all pumps are currently approved for use with Prialt. Drugs approved for intrathecal administration must meet additional safety standards over those administered in other ways because the spinal cord and brain tissue are highly sensitive to preservatives or infectious organisms such as bacteria or viruses, which can lead to serious complications, the agency noted.
FDA has found that patients are sometimes being treated with medications that are not approved (including compounded medicines as well as hydromorphone, bupivacaine, fentanyl, and clonidine) for use with an intrathecal implanted pump. The reasons sometimes cited for the use of drugs not approved for use with implanted pumps have included that approved medications listed in the pump labeling may have undesirable side effects or may fail to deliver adequate pain relief for some patients.
The agency said implantable intrathecal pump failure is more frequent with the use of medicines not approved for use with the pump. For example, some medicines or fluids may contain preservatives or other characteristics that can damage the pump tubing or lead to corrosion of the pumping mechanism. This may cause the implanted pump to perform in unexpected ways, including motor stalls, which ultimately stop the medication delivery, leading to potential opioid withdrawal. When a pump fails, patients must undergo surgery to remove or replace the pump.
Dosage errors may also occur when medicines that are not approved for intrathecal administration are nonetheless used in these pumps. Programmable implanted pumps have dose calculation software that provides options for users to select pre-programmed medicines and concentrations identified in the approved pump labeling to help prevent unintended dosing errors. The accuracy of the software calculations depends on using the approved medicine, medicine concentration, and medicine characteristics. For example, if there is more than one medicine in the pump reservoir, the pump software can only calculate the dose based on the infusion rate of a single medicine.